Tried to set up an out of office reply on Mail and sent it out to my entire mailbox. How to set up for just incoming?

Who is your Mail account with? It is usually best to set it up with the web interface rather than from mail because the web interface usually has more options.

OK. Who is your mail account with?

Do you host it yourself? Also does it have a web interface? Is it POP or IMAP?

Choose Mail > Preferences, and then click Rules.

To review an example of a rule, select a provided rule and click Edit. To close the rule, click Cancel.

Click Add Rule, and then type a descriptive name for the rule.

Indicate whether any one or all of the conditions must be true for the rule to be applied to a message.

Specify the conditions.

Use the pop-up menus and entry fields. Click Add ➕ to add another condition.

From the first pop-up menu, you can choose Edit Header List to use other header fields, such as Cc, in conditions. To add your own header, click Add ➕ in the Message Headers window.

Choose actions to perform on messages that meet the conditions. To specify multiple actions, click Add (+).

Here is a screenshot of an example of what you would do:

Hope this helps,

xeni

Sounds like you created a rule to auto-reply, then told Mail to apply it to the messages in the currently selected mailbox when asked.

I don't generally recommend using rules in Mail to create auto-replies like this. The problem is that it creates the potential for an infinite mail loop. In other words, Mail receives a message and sends an auto-reply. That reply then generated an automated response from the recipient, which triggers an auto-reply from you again, which triggers a response from the recipient again, and so on until one or both mailboxes fill up and cannot receive any further email.

Plus, there's the added problem of having to leave your machine running, without it falling asleep, with Mail running 24/7 while you're gone. That can be a problem, and isn't the most reliable. (Consider what happens if the power goes out, for example.)

Instead, look into what options are provided by your email server for vacation messages. Those auto-responses usually are designed to prevent infinite mail loops, and that does not rely on your computer staying on the whole time.